Wireless communication systems are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Wireless communications networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. Examples of such networks include networks based on the Global System for Mobile Communications (GSM), the Universal Mobile Telecommunications System (UMTS), and Long Term Evolution (LTE), which are defined by the 3rd Generation Partnership Project (3GPP), as well as cdma2000 1× and 1×EV-DO, which are defined by the 3rd Generation Partnership Project 2 (3GPP2), among others.
Wireless communication systems may be accessed by various types of devices adapted to facilitate wireless communications, where multiple devices share the available system resources (e.g., time, frequency, and power). Examples of such wireless communications systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems and orthogonal frequency-division multiple access (OFDMA) systems. Multiple types of devices are adapted to utilize such wireless communications systems. Such devices may be generally referred to as access terminals.
A service provider (or network operator) may deploy multiple radio access technologies in a given wireless communication system to enable users of differently capable access terminals to access the service provider's system. For example, a service provider may deploy radio access technologies such as an LTE (eUTRA) network, an Evolution-Data Optimized cdma2000 (1×EV-DO) network (as defined by the 3GPP2 standards body), a cdma2000 1× network (also defined by 3GPP2), a UMTS network utilizing a Time Division Synchronous Code Division Multiple Access (TD-SCDMA) air interface or a wideband CDMA (W-CDMA) air interface, a network such as GSM, or any other suitable network.
In some instances, access terminals may be capable of communicating on two or more different radio access technologies. Such access terminals are often referred to as hybrid devices or hybrid access terminals. One common hybrid access terminal is a single-SIM device that may be referred to as a 1×/DO hybrid access terminal, which is capable of communicating on both 1×EV-DO networks and on cdma2000 1× networks. Another example of a hybrid access terminal is a dual- or multi-SIM device, which may be capable of communicating on any two or more different networks corresponding to two or more respective user subscriptions. That is, certain wireless networks identify subscribed users by means of a subscriber identity module (SIM).
Some wireless devices support multiple concurrently installed SIMs and may provide functionality corresponding to two or more SIMs utilizing a single communication interface or transceiver. For example, some access terminals support dual-SIM dual-standby (DSDS) functionality, wherein standby functions, such as performing idle mode procedures like receiving and responding to page messages, may be performed on two subscriptions on different radio access technologies (RATs) utilizing a single communication interface. Further, such DSDS technologies are frequently able to support active communication channels on one RAT while enabling tune-away operations to perform idle mode procedures on the other RAT, again, sharing a single communication interface. The two concurrent subscriptions may include some combination of circuit-switched (CS) and packet-switched (PS) traffic.